\\[-1.8ex] Soil Heterogeneity & $-$1.187$^{***}$ & $-$1.187$^{***}$ & $-$0.722$^{***}$ & $-$0.632$^{***}$ & $-$0.478$^{***}$ & $-$0.487$^{***}$ \\ 
  & (0.263) & (0.263) & (0.230) & (0.229) & (0.168) & (0.162) \\ 
\\[-1.8ex] 
Observations & 23,322 & 23,322 & 23,322 & 23,322 & 23,322 & 23,260 \\ 
R$^{2}$ & 0.017 & 0.017 & 0.155 & 0.195 & 0.213 & 0.215 \\ 
